Here are some commonly used shortcut keys for Microsoft Office :

General:

Ctrl + N - Create a new document

Ctrl + O - Open an existing document

Ctrl + S - Save a document

Ctrl + P - Print a document

Ctrl + Z - Undo the last action

Ctrl + Y - Redo the last undone action

Word:

Ctrl + C - Copy selected text or object

Ctrl + X - Cut selected text or object

Ctrl + V - Paste copied or cut text or object

Ctrl + B - Apply bold formatting to selected text

Ctrl + I - Apply italic formatting to selected text

Ctrl + U - Apply underline formatting to selected text

Ctrl + A - Select all content in a document

F7 - Run a spelling and grammar check

Excel:

Ctrl + C - Copy selected cells or range

Ctrl + X - Cut selected cells or range

Ctrl + V - Paste copied or cut cells or range

Ctrl + Z - Undo the last action

Ctrl + Y - Redo the last undone action

F2 - Edit the selected cell

Ctrl + F - Open the Find dialog box

Ctrl + H - Open the Replace dialog box

PowerPoint:

Ctrl + C - Copy selected slide or object

Ctrl + X - Cut selected slide or object

Ctrl + V - Paste copied or cut slide or object

Ctrl + A - Select all slides or objects

F5 - Start a slideshow from the beginning

Shift + F5 - Start a slideshow from the current slide

Ctrl + P - Print a presentation

Ctrl + D - Duplicate selected slide or object